I didn't take a 'before' photo of mine - so here's one off the interweb showing severe corrosion.
My car had tiny bubbles of corrosion starting to appear around the wiper stalks in front of the front screen. I had the windscreen removed and the entire area fully repaired by Langley Autocraft (highly recommended - Pete the owner is the PCGB bodyshop panel expert and has a superb 993 and 996). The ned result is superb. A true, mirror like finish. They guy's a genius with a spray can.
No bubbles anymore
993 windscreens are notoriously problematic to remove and replace and require an expert with previous experience! Very often, the screen can squeak as it moves slightly in the scuttle which is annoying.
I had the screen replaced with a lining of teflon tape which ensures a squeak free result.
At the same time, I had the small rubber seals replaced around the edges of the screen and the leading edge of the bonnet. Close-ups below.
Rubber Seals replaced